And after one of the mildest winters on record, vegetable crops in a certain Victorian walled garden in deepest Perthshire are already approaching glut status. Lush greenery, contained in various massed ranks by canes, cloches, strings and wires, is yielding to a rainbow harvest of reds, yellows and purples. Native Black bees dip gingerly in and out of flowerheads while frogs and toads await their next snack of garden pests from the depths of their sunken slate pond.
For Scotland's top chef Andrew Fairlie, this newly acquired three-acre kitchen garden is proving his salvation - both professionally and personally. As he potters among the plants, picking and sniffing and tasting as he goes, he looks up and says simply: "Just feel it. It might be peaceful and quiet, but there's an energy in these plants that is so different from the crazy energy of the kitchen. Having this garden is the most exciting thing that's happened since the start of my career. It's given me a new direction and a whole new lease of life."
That's quite a statement, from the A-list chef whose two-Michelin-starred restaurant at the Gleneagles Hotel - soon to host the Ryder Cup - has been voted the best in the UK and one of the top 10 restaurants in the world; Fairlie himself, who left school at 15 and won the first Roux Scholarship at 20, last year joined the international culinary elite as one of only 160 Grands Chefs Du Monde.
The accolades keep on coming, but like an increasing number of trend-aware chefs, Fairlie has been hankering after the ultimate means of sourcing local, seasonal produce at the peak of freshness. And earlier this year, while at the Beatson oncology centre in Glasgow enduring six weeks of radiotherapy in a bid to stop the epileptic seizures he's been experiencing up to 20 times a day following the partial removal of a brain tumour in 2005, he could hold on to the comforting knowledge that back at base he had finally realised his long-held dream.
So significant is the grow-your-own movement in the world's top kitchens that some chefs are taking a year out to learn about gardening. Fairlie, who grew up in a Letham council house with just a small front garden and left Perth Academy with no qualifications, has gone one step further by appointing his own personal horticultural tutor.
In the months before radiotherapy began in January to shrink and "dry" the remaining tumour - following an unsuccessful second course of chemotherapy in 2012 which had left him feeling like "shite", nauseous and exhausted - he'd begun to lay down the roots of his new plan.
Behind the high stone walls of the old neglected market garden, Fairlie's newly appointed head gardener Jo Campbell had been working steadily to transform the space into a continuous source of ethically grown key ingredients to further enhance her boss's world-class cooking. Previously head gardener of the two-acre kitchen garden at Raymond Blanc's two-Michelin-star Le Manoir aux Quat'Saisons in rural Oxfordshire, she'd been travelling in India when she spotted Fairlie's job advertisement on Twitter. She got the gig, started last August, and is now so smitten that she's lured Le Manoir colleague Tina Barnes as her assistant (or "sous-chef"). Fairlie's partner Kate White has joined the team as apprentice gardener. It remains to be seen whether the other four women in his life - Ilona, 24, and Leah, 18, his two daughters from his first marriage to ex-wife Ashley; and Kate's daughters, aged 13 and nine - will join the venture.
As we survey the new raised beds, erected where the garden's old cold frames used to be, there are baby leeks, Sweet Florence baby fennel, baby radish, early salad onions, a huge range of beetroot varieties, salfisy, chicory, perilla purple borage, Stone Yellow carrots, chervil, anise hyssop, lemon bergamot. Close by are pineapple sage, golden sweet Shiraz purple mangetout beans. There are apples and plums. The range and volume of produce is breathtaking, and all the more so since Campbell is only in her first season here.
"We're very lucky to get Jo," says Fairlie. "She's a natural forager, very into plants and unusual flavours. We're hoping to grow forgotten heritage varieties from the area. I am sure there are many ancient Scottish flavours that haven't been rediscovered yet.
"This has always been the bit of our business that has been missing and it's a revelation to me. I'm amazed there are so many varieties of so many species that grow well here. I didn't even know red and white Alpine strawberries grew in Scotland. My ignorance has been costing me a fortune," he jokes.
The galvanising influence of the garden on Fairlie's menu is striking. There's a new lightness of touch shot through with an experimental chutzpah in his raspberry and beetroot sorbet, tarragon ice-cream, and a new range of dessert sorbets including lemon verbena and lemongrass. On the main menu there's a pea and crowdie gratin, an accompaniment of marinated courgettes and grilled cucumber, and confit onions and summer vegetables to go with slow-cooked beef cheek.
Fairlie says his cooking method, and that of head chef Stevie McLaughlin, have completely changed. Some dishes actually headline the greenery: garden radish with crushed broad beans is listed above a dish of seabass with chervil juice; a heritage tomato salad gets first billing over a dish of confit duck wings; warm Jersey Royals with asparagus top a dish of lamb.
So is the prized Scottish beef, lamb, shellfish and seafood on Fairlie's double-Michelin menu now playing second fiddle to his freshly harvested produce? "People are eating more vegetables on the plate," he says. "The market menu will now change every day, and the a la carte is much more produce-led. The traditional main ingredients are almost taking a step back. The flavours and colours of this fresh produce are incredible and the pastry chef is using more vegetables and herbs than ever before."
Where normally all veg is cooked in advance and put in the fridge, now it's all prepared to order - and not cooked in water. Fairlie and McLaughlin have devised their own "sous vide for veg" method, using the plancha (hot plate) and an upturned saucepan. Fresh veg roots are kept on for a more dramatic presentation; as much as possible of each plant is used. Young broad bean flowers are used for decoration; the young beans are crushed with mint for canapes; the edible leaves themselves are deployed as "plates". Chervil root, leaf, flower and seeds are also used.
The new approach is most evident in a stunning grilled baby gem lettuce heart and herb salad accompaniment for a veal dish on the a la carte. The two vertical halves of the lettuce are vacuum-packed to change its texture. I watch as McLaughlin removes them, grills the edges with a blowtorch to add flavour, and proceeds to build a medley of mandolin-thin slices of raw radish, carrot, baby leeks and baby fennel on top, finishing with wild pansy, marigold and cornflower petals, chive flowers and lemon verbena leaves. The plate is dotted with a new house creation of chervil juice with passionfruit and rapeseed oil. "The colour and flavour is more vibrant when you grow your own, and you really do start to think like a gardener," says the head chef, who recently starred in the Scottish heat of BBC Two's Great British Menu.
He and Fairlie regularly visit the garden with their sous and commis chefs. Front-of-house staff go weekly to learn about what's growing, so they can impart that information to diners. Pots of different types of cresses grown in the Victorian greenhouse are placed in decorative red perspex boxes on tables so that diners can touch, taste and discuss them.
"When you have things that are only here for one or two days, and see things change on a daily basis, it forces you to think more creatively and keep on moving," explains Fairlie. "Jo might ring and tell us she has 150 white turnips ready to be delivered first thing in the morning. We have to use them as they come though. If they're too big, we'll use them for a delicious veloute. The magical thing about having the garden is that we'll always find other uses for things.
"It's such a refreshing change from having all your produce delivered in boxes from a market far away. This was the only part of the menu we didn't have control over. Before, we'd have a sheet of faxes telling us what was available for the week. We'd pick what we wanted then hope for the best and sometimes it wasn't up to scratch when it arrived. Now, we are free to do our own thing. You have to take risks with some of the stuff but if you always play safe you'll never develop." He bats off my suggestion of a third Michelin star come the October release of the new Michelin Guide, but given these fascinating new developments it's surely not entirely out of the question.
Fairlie's positive, can-do approach is typical of the man whose achievements are all the more astonishing given the rigours of his medical condition. When the seizures began in 2010 after five years on post-operative medication for epilepsy, consultants had advised chemo to control them.
He started his first course in 2011 but incredibly, interrupted it to climb Mt Kilimanjaro to raise funds for the Hospitality Industry Trust. His second dose was last September but it wasn't entirely effective; he could be fine for a couple of weeks, then the seizures would arrive at the rate of 20 a day.
Last year he described the experience to me: "The seizures last anything from 10 to 45 seconds and I can be either standing up or lying down when it happens. They only affect my left arm and leg." His left index and ring fingers are pretty useless, and his left arm is "lazy". Asked if this was dangerous for a chef, who might be using a sharp knife or holding a hot pan, he replied: "I'm aware of when it's going to happen. I get an 'aura' of a few seconds' warning so I can put down anything I'm holding. Staff know to leave me alone until it's over."
Diners increasingly look for a more casual two-star culinary experience these days, and the flexible, daily changing Du Marche menu (which Fairlie describes as "freefall style") is so popular that it accounts for a quarter of everything he cooks. Yet he doesn't believe in following fads. "It has to be a natural, organic process for us. We went through a silly period when we tried to do what Noma, El Bulli and El Celler were doing, but it wasn't natural to us. Customers said they didn't come here for that sort of thing."
The rarity of the Scottish "terroir" (the natural environment in which ingredients are produced) is "massive", he says: "People come from all over the world for this."
Campbell, who is originally from North Yorkshire and has spent many years growing for top kitchens, agrees. "I keep thinking I'm not really in Scotland, because things are growing really, really quickly," she says. "People think there are certain things you can't grow in Scotland, but if you work with the weather and find natural alternatives to enhance growing, it's absolutely fine." She and her team are revisiting old Scots gardening techniques like cloching and clamping. "Having said that, it takes at least a whole year to learn a garden, and we're still finding out about the vagaries of this one and the Perthshire climate. It's a challenge after Le Manoir, where we grew 90 types of vegetable and 70 varieties of herb, but it's fantastic to be creating something new from something so old.
"It's all about working with Andrew and Stevie. The 'see it, use it' approach is giving them new ideas. We see them walking around the garden and their minds are whirring.
"That's why I love working with chefs. They think differently from gardeners and are very creative. When we harvested new mangetout peas, Andrew asked if he could have the pea foliage. He and Stevie extracted the juice and used it in a pannecotta. When a sudden hail storm smashed the young spinach plants to pieces, I thought the crop was ruined but they took it, extracted the chlorophyll and used it for pasta and a spinach filling.
"Yesterday Stevie came down and we showed him the bulb fennel. He took one look and said, 'Yep, we'll have 100 of those'. He was very excited."
Campbell is an active member of an international group of chef-growers who share photographs and knowledge on a daily basis. Through Twitter and Instagram she follows growers all over the world from Tasmania, the US, Australila, Italy and France, bringing in new ideas to her garden, and then to the kitchen, all the time.
As we start to pack up the tools of our own trade, I ask Fairlie if treatment has been successful. He reveals that he has been seizure-free for five months, and counting. "The garden is a very calming influence and I am sure it has had a beneficial effect," he says cautiously. "Fingers crossed that I won't need more follow-up chemotherapy." As he fondly surveys the fairytale scene before him, it's clear he knows more than most that in the fiercely competitive world of international cuisine, what really matters is taking time out to cultivate your own garden.